We have devised a hybrid artificial internal organ (such as the hybrid artificial liver), where a suspension of cells and tissue fragments (such as from the liver) is kept in contact with a microporous membrane, and the other side of which is exposed to flowing fresh blood from a recipient. The overall configuration for the reactor is similar to the spiral coiled membrane lung, except that the suspension of cells - tissue fragments is replacing the gas phase in the membrane lung. The biochemical activity of cells thus continues, and such a reactor can thereby supplement the failing organ of a patient.